In U.S. Pat. No. 4,609,780 there is disclosed an electronic secure entry system, apparatus and method. In that apparatus and system, a battery is provided in the apparatus and system for operating the electronics within the lock box. A card is provided for use with the lock box. In one embodiment, a keyboard is provided as an integral part of the lock box in which the private code of the user can be inserted. In another embodiment a card is provided which is separate from the lock box and which can be utilized to insert a private code by communicating with the electronics in the box by sensor coils carried by the box. In co-pending application, Ser. No. 899,533, filed Aug. 22, 1986 there is disclosed an electronic access card which can be utilized with a lock box of the type described in U.S. Pat. No. 4,609,780, but which carries its own electronics and a battery type power supply. In application Ser. No. 899,338 filed Aug. 22, 1986 there is disclosed an electronic access card of the type disclosed in application Ser. No. 899,533 but with a visual display. In connection with the foregoing, it has been found that it is desirable to provide additional features for an electronic lock box and access card which are not within the capabilities of the lock box and access cards of the type hereinbefore disclosed. As for example, it is desirable to provide a access card which has minimal, if any, power requirements when it is not being operated. There is therefore a need for a new and improved electronic lock box, access card, system and method.